Petroliferous fluids produced from oil and gas wells will frequently contain normally solid paraffinic hydrocarbons which tend to accumulate in the well bore and in the equipment utilized for producing the petroliferous fluid. In addition, the normally solid paraffins frequently tend to accumulate in transportation lines, storage vessels, and other equipment wherein the petroliferous fluids are processed. This presents a serious problem in that the deposition of paraffins interferes with the production, transportation, storage, processing, etc. of the petroliferous fluids containing such paraffinic materials. Paraffin deposition may proceed to the point where production is completely interrupted. In the past the problem of removing paraffin deposits from pumping wells and flow lines has been attacked in a number of ways. The oldest method, and perhaps the most effective heretofore, was to clean the well mechanically, e.g. by scraping. This method resulted in lost production time and high labor costs and required special tools, all of which was often too expensive to be economically feasible.
It has also been common practice to try to restore the flow of a well by cleaning the well with chemical solvents. In order to do this, hot oil or solvent has been introduced in liquid phase into the well in an effort to dissolve the undesired materials. In actuality, however, the solvents used in the prior art, have been effective only to dissolve the paraffins and other hydrocarbons that are readily soluble in organic media. Moreover, the use of such solvents has been a time-consuming and costly operation and has resulted in considerable loss of production time. Worst of all, perhaps, is that the prior art method of cleaning wells, by the use of solvents, have been largely ineffective and in many instances have served only to worsen the fouling of the well. This is because when the paraffin and other relatively soluble constituents of the sludge are removed by solvent, the proportion of insoluble soil-like constituents of the sludge rises with the result that the sludge becomes even denser and less permeable than gas and oil.
Yet another attempt to remove paraffin deposits from pumping wells and flow lines resides in utilizing an acid-bas reaction to generate heat in situ in order to dissolve the deposited paraffin. All of these cleaning operations reported in the prior art however, have been less than satisfactory for one reason or another. For instance, it has been very difficult to control the heat of reaction necessary so as to provide the desired uniform high temperature needed for efficient paraffin removal operation without redeposition of the paraffin and/or accelerated damage to the equipment.